Naturally occurring molecules which exhibit potentially beneficial pharmacological properties are isolable from a range of environments, such as marine, plant and microbial sources. One example of such molecules is the general class of compounds known as the Lamellarins. These polyaromatic alkaloids are isolated from marine sources and comprise a fused polyaromatic framework. Lamellarins C and D have been shown to cause inhibition of cell division in a fertilised sea urchin assay, whereas Lamellarins I, K and L all exhibit comparable and significant cytotoxicity against P388 and A549 cell lines in culture. Recently, Lamellarin N has been shown to exhibit activity in lung cancer cell lines by acting as a Type IV microtubule poison. Furthermore, these compounds have also been shown to possess cytotoxic activity on multidrug resistant cells as well as efficacy as non-toxic modulators of the multidrug resistant phenotype and, therefore, afford an attractive potential source of chemotherapeutic agents.
However, the potential clinical usefulness of the Lamellarins is severely limited by the modest quantities produced naturally as well as the difficulties involved in their isolation. Steglich & coworkers, in Angew. Chem. Int. Ed. Eng. 1997, 36, 155, have described a biomimetic sequence for the synthesis of Lamellarin G trimethyl ether, however, the process is limited in that it lacks regiochemical control and does not readily lend itself to the specific substitution patterns dictated by the natural products. There is a need, therefore, for a synthetic process which enables the production of the Lamellarins and analogues thereof.